Has anyone actually tried doing challenges with different classes?I find that ,save for a few cases (Priest Gold with a Warlord, hah! ), a good number of them is either not doable or pretty hard with other classes.

Well, that is the point of class challenges. A dungeon incredibly difficult, but doable with that class because that class is tailored to beat it (with a few exceptions like Berserker Gold with a wizard).

Yeah, doesn't work any longer.Bloodmage Bronze was fun,effectively allowing you to have two classes at once. Although for some reason the +1 mana per bloodpool didn't work for other classes. Still, blood monk was fun.

Berserker Gold is kind of stumping me. How are you intended to beat that, without relying on BYSSEPS (if it's even possible for it to spawn) or a lucky Piercing Wand from a shop? Elvish/Gnomish Berserker, then buy Mystic Balance?

Also, what pact should I choose? I like Body Pact, since it's pretty easy to pay for with Mystera and still have quite a bit of piety left over for her boons, but I don't really like touching all those Succubi...

You effectively will not be attacking the boss (except once or twice). You can stack up burning with Whurgarble and then elf+mystic balance for the win, although Whurgarble is not necessary. You should also use Refreshment on the boss

Yeah, you're supossed to go full spellcaster mode with an elf-berserker. The whole dungeon is tailored to destroy the typical berserker, so don't worry too much about your offensive stats and just burn everything down with the helpf of an occasional normal attack.

Personally, I prefer the alchemists pact - it allows you to squeeze in a few exp more, hopefully enough for another levelup once you spent everything. Spend your piety on mystic balance, mana, and flames once you've defeated all the popcorn.